Table of Contents
Oracle Database - Mutexes
About
Mutexes are lock from the type System (internal database structures).
A mutual exclusion object (mutex) is a low-level mechanism that prevents an object in memory from aging out or from being corrupted when accessed by concurrent processes. A mutex is similar to a latch, but whereas a latch typically protects a group of objects, a mutex protects a single object.
Mutexes provide several benefits:
- A mutex can reduce the possibility of contention.
Because a latch protects multiple objects, it can become a bottleneck when processes attempt to access any of these objects concurrently. By serializing access to an individual object rather than a group, a mutex increases availability.
- A mutex consumes less memory than a latch.
- When in shared mode, a mutex permits concurrent reference by multiple sessions.
